Digital Tax Service · Guidance

What a Self Assessment tax return costs

Last updated: Maintained by the Digital Tax Service editorial team
Making Tax Digital digital record keeping and quarterly updates to HMRC, in navy and gold

The costs on each route

RouteCostRight when…
DIY via HMRC onlineFreeSimple affairs, comfortable with the forms
Our fixed fee (standard SA100)£199 + VATDirectors, dividends, landlords, first-timers
Complex return (quoted first)From £199 + VATForeign income, capital gains, messy records
Doing nothing£100 → £1,600+Never — penalties accrue even with no tax due

The real cost of missing 31 January

The “doing nothing” row is worth spelling out, because HMRC’s late-filing penalties apply even if you owe no tax:

  • 1 day late — an automatic £100 penalty.
  • 3 months late£10 a day for up to 90 days (up to £900 on top).
  • 6 months late — a further £300 (or 5% of the tax due, if higher).
  • 12 months late — another £300 (or 5%), and more in serious cases.

Left unaddressed, that reaches £1,600+ — before any late-payment penalties and interest on the tax itself. Set against that, a fixed fee to have it done on time is cheap insurance.

What the fee actually buys

  • Every income source in the right box — salary, dividends, interest, rent, with the paperwork to back it
  • Claims you might not know about — allowable expenses, pension relief for higher-rate taxpayers, marriage allowance, gift aid
  • Your bill (or refund) confirmed before filing, with payment dates and payments on account explained
  • Filed online with HMRC and the submission receipt sent to you

For directors we prepare the return from the company’s own records — salary and dividends always match what the company reported, which is exactly what HMRC’s systems check.

Self Assessment for company directors

Already late? The maths favours speed

The £100 penalty is sunk — but £10/day starts three months after the deadline, and the 6-month penalty is the higher of £300 or 5% of the tax due. Records to us this week beats records to us next month, every time. Call 0114 327 1480.

All our fixed fees

Frequently asked questions

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